4 Buffer Mode

Buffer mode is very similar to File mode, except that instead of
tracking the current directory and all files available there, the
current list of Emacs buffers is shown.

These buffers can have their tags expanded in the same way as files,
and uses the same unknown file indicator (see File Mode).

Buffer mode does not have file operation bindings, but the following
buffer specific key bindings are available:

k

Kill this buffer. Do not touch its file.

r

Revert this buffer, reloading from disk.

In addition to Buffer mode, there is also Quick Buffer mode. In fact,
Quick Buffers is bound to the b key. The only difference between
Buffers and Quick Buffers is that after one operation is performed
which affects the attached frame, the display is immediately reverted to
the last displayed mode.

Thus, if you are in File mode, and you need quick access to a buffer,
press b, click on the buffer you want, and speedbar will revert
back to File mode.